Graduate Student Department of Physics and Astronomy
University of Pennsylvania, Philadelphia, U.S.A.

office: DRL 2N13C
email: dbeller [at] sas.upenn.edu

I work in the field of theoretical soft condensed matter physics, whose aim is to model and understand fluid materials more complex than simple liquids, such as polymers, colloidal suspensions (e.g. milk and paint), liquid crystals, foams, and sand -- many of which we interact with on a daily basis. Deep physical principles turn out to be highly effective in allowing us to describe these complicated systems.

In particular, I conduct theoretical and numerical research on liquid crystals, which have properties intermediate between those of a liquid and those of a solid. The molecular arrangements of solid crystals exhibit much more order than the molecular arrangements of liquids, and a wide variety of liquid crystal phases are defined by the diverse types of ordering that are possible between these two extremes. Because of their optical properties and the ease with which they can be aligned with electric fields, liquid crystals are today a dominant choice for electronic displays in TVs, computers, cell phones, etc. Liquid crystalline ordering is also an important principle in many other contexts, such as in the membranes of living cells and in soap films.

Recently, much scientific attention has turned to the study of defects in liquid crystals -- places in the material where the liquid crystalline order is required to break down for geometric, topological, or energetic reasons. Defects interact with one another via forces mediated by the liquid crystal. As a result, there are exciting possibilities for the use of liquid crystalline defects in self-assembled materials. Our goal is to identify new principles by which complex boundary surfaces and inclusions of colloidal particles may be used to promote desired arrangements of liquid crystalline defects for use in micro-scale functional materials.